urths of an inch long, are dark brown.
When the cones are ripe the scales and bracts fall off, setting the
seeds free to fly to their predestined places, while the dead spike-like
axes are left on the branches for many years to mark the positions of
the vanished cones, excepting those cut off when green by the Douglas
squirrel. How he gets his teeth under the broad bases of the sessile
cones, I don't know. Climbing these trees on a sunny day to visit the
growing cones and to gaze over the tops of the forest is one of my best
enjoyments.

_July 29._ Bright, cool, exhilarating. Clouds about .05. Another
glorious day of rambling, sketching, and universal enjoyment.

_July 30._ Clouds .20, but the regular shower did not reach us, though
thunder was heard a few miles off striking the noon hour. Ants, flies,
and mosquitoes seem to enjoy this fine climate. A few house-flies have
discovered our camp. The Sierra mosquitoes are courageous and of good
size, some of them measuring nearly an inch from tip of sting to tip of
folded wings. Though less abundant than in most wildernesses, they
occasionally make quite a hum and stir, and pay but little attention to
time or place. They sting anywhere, any time of day, wherever they can
find anything worth while, until they are themselves stung by frost. The
large, jet-black ants are only ticklish and troublesome when one is
lying down under the trees. Noticed a borer drilling a silver fir.
Ovipositor about an inch and a half in length, polished and straight
like a needle. When not in use, it is folded back in a sheath, which
extends straight behind like the legs of a crane in flying. This
drilling, I suppose, is to save nest building, and the after care of
feeding the young. Who would guess that in the brain of a fly so much
knowledge could find lodgment? How do they know that their eggs will
hatch in such holes, or, after they hatch, that the soft, helpless grubs
will find the right sort of nourishment in silver fir sap? This
domestic arrangement calls to mind the curious family of gallflies.
Each species seems to know what kind of plant will respond to the
irritation or stimulus of the puncture it makes and the eggs it lays, in
forming a growth that not only answers for a nest and home but also
provides food for the young. Probably these gallflies make mistakes at
times, like anybody else; but when they do, there is simply a failure of
that particular brood, while enough to perpetuate